雙週期性 shuāng zhōu qī xìng

DEFINITIONS

  1. (math.) double periodicity

CHARACTERS

雙 shuāng set of two, pair, couple; both
週 zhōu week; turn, cycle; anniversary
期 qī
HSK 1
period of time; date; time limit
性 xìng
HSK 4
nature, character, sex